This invention pertains to lock structure and, more particularly, to a window lock of a type especially useful with a casement window, wherein a keeper is mounted on the sash and the locking structure is mounted on the window frame. The sash can be drawn into locked position against the frame and initially cracked open during opening movement of the window to facilitate either manual or actuator mechanism opening of the window.
Locks for windows, such as casement windows, are generally known, wherein a keeper is mounted on the sash and a base with a pivoted handle is mounted on the frame whereby the casement window may be tightly closed and held in locked position. It is also known in such lock mechanisms to have a kick-out feature to free a frozen or swollen sash. These prior art structures did not have a pivotally-mounted handle carrying a locking element for both bodily and rotational movement to coact with a keeper.
A prior art search included U.S. Pat. Nos. 40,819, 51,222, and 352,617. The first of these patents discloses a window sash fastener wherein a pair of rollers are each rotatably mounted on an individual pivoted handle and have gear teeth for rolling along a fixed arcuate gear to move to and from a wedging position with respect to a window sash. The second patent is similar to the first, with structure for a single roller. The last-mentioned patent has a latch with rotational and reciprocable movement which is operated by a knob with an eccentrically positioned gear which interfits with gear teeth on the latch.
The aforsaid prior art patents do not disclose a lock mechanism having the structure or the operational features and advantages set forth hereinafter.